Synthesis and characterization of a mercury-containing metalloborylene

The reaction of phenylmercuric chloride with an anionic dimanganaborylene [Cp2(CO)4Mn2B]Na led to the formation and isolation of a trimetalloborylene featuring at previously unreported bond between mercury and a single boron atom. Examination by 199Hg NMR displayed a small 11B-199Hg scalar coupling (J = 103 Hz), confirming the electronic interaction of the two atoms. The use of ETS-NOCV analysis indicated the nature of bonding to be s-donation from a B-Mn p-orbital to Hg, in conjunction with weak Hgd?p* back-donation.